<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Bootstrap初步使用</title>
    <link rel="stylesheet" href="./css/bootstrap.min.css">
    <style>
        @media (min-width: 800px){
            /* 浏览器宽度大于800px时，显示700px的容器背景颜色 */
            .container{
                width: 700px;
                background: #ccc;
            }
        }
        div[class^=col-md]{
            box-sizing: border-box;
            padding: 20px;
            background: #58bc58;
            border: 5px solid #000;
        }
    </style>
</head>
<body>
    <!-- 1.容器container -->
    <div class="container">
        <div class="row">
            <!-- 一行最多12列：lg大尺寸、md中尺寸、sm小尺寸、xs超小尺寸 -->
            <!-- 当缩小屏幕时，h1独占一行，h2、h3平分第二行 -->
            <div class="col-md-5 col-xs-12">h1</div>
            <div class="col-md-4 col-xs-6">h2</div>
            <div class="col-md-3 col-xs-6">h3</div>
        </div>
    </div>
    <!-- 流式布局 -->
    <div class="container-fluid">
        <div class="row">
            <div class="col-md-5 col-xs-12">h1</div>
            <div class="col-md-4 col-xs-6">h2</div>
            <div class="col-md-3 col-xs-6">h3</div>
        </div>
    </div>
</body>
</html>